How to "capitalize" on a viral post?

I'm managing a FB page and our posts usually have a reach of 2-3k. Suddenly I have a post with a reach of 295k and growing, 23k interactions, 3,6k "shares" and almost 400 new followers in less than three days. I have no idea if I should just lean back and enjoy the show or if I should be planning some kind of follow-up post or making some kind of plans or analysis of the situation to make the most of this.

I'm not interested in making money of it, just growing and maintaining the community around the page. Does anyone have any suggestions about my next move?

Since you're managing a FB page, you can pin that specific post to the top to keep it visible, while you update the page with more content.

What kind of content was that post about by the way? You might need to act fast if the sudden influx of interest resulted from haters with an axe to grind against you, your businesses or relatives in particular. If it's just edgy commentary of the day, it's not rare for those to gain this much visibility with many active FB users resharing it on their own timelines.

It was kind of a short PSA, to not scare small children with threats about the police coming to lock them up if they are naughty. Very few haters though, as far as I can see. The reach has passed 500k now.